Commit message: i2c: fix stack buffer overflow vulnerability in i2c md command

When running "i2c md 0 0 80000100", the function do_i2c_md parses the
length into an unsigned int variable named length. The value is then
moved to a signed variable:

    int nbytes = length;
    #define DISP_LINE_LEN 16
    int linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes;
    ret = dm_i2c_read(dev, addr, linebuf, linebytes);

On systems where integers are 32 bits wide, 0x80000100 is a negative
value to "nbytes > DISP_LINE_LEN" is false and linebytes gets assigned
0x80000100 instead of 16.

The consequence is that the function which reads from the i2c device
(dm_i2c_read or i2c_read) is called with a 16-byte stack buffer to fill
but with a size parameter which is too large. In some cases, this could
trigger a crash. But with some i2c drivers, such as drivers/i2c/nx_i2c.c
(used with "nexell,s5pxx18-i2c" bus), the size is actually truncated to
a 16-bit integer. This is because function i2c_transfer expects an
unsigned short length. In such a case, an attacker who can control the
response of an i2c device can overwrite the return address of a function
and execute arbitrary code through Return-Oriented Programming.

Fix this issue by using unsigned integers types in do_i2c_md. While at
it, make also alen unsigned, as signed sizes can cause vulnerabilities
when people forgot to check that they can be negative.

Signed-off-by: Nicolas Iooss <nicolas.iooss+uboot@ledger.fr>
Reviewed-by: Heiko Schocher <hs@denx.de>
CVE: CVE-2022-34835
CWE: CWE-787
Vulnerability description: In Das U-Boot through 2022.07-rc5, an integer signedness error and resultant stack-based buffer overflow in the "i2c md" command enables the corruption of the return address pointer of the do_i2c_md function.

Project: u-boot
File: i2c.c

static int cmd_i2c_set_bus_num(unsigned int busnum)
{
	struct udevice *bus;
	int ret;

	ret = uclass_get_device_by_seq(UCLASS_I2C, busnum, &bus);
	if (ret) {
		debug("%s: No bus %d\n", __func__, busnum);
		return ret;
	}
	i2c_cur_bus = bus;

	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_probe(struct cmd_tbl *cmdtp, int flag, int argc,
			char *const argv[])
{
	int j;
	int addr = -1;
	int found = 0;
#if defined(CONFIG_SYS_I2C_NOPROBES)
	int k, skip;
	unsigned int bus = GET_BUS_NUM;
#endif	/* NOPROBES */
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *bus, *dev;

	if (i2c_get_cur_bus(&bus))
		return CMD_RET_FAILURE;
#endif

	if (argc == 2)
		addr = simple_strtol(argv[1], 0, 16);

	puts ("Valid chip addresses:");
	for (j = 0; j < 128; j++) {
		if ((0 <= addr) && (j != addr))
			continue;

#if defined(CONFIG_SYS_I2C_NOPROBES)
		skip = 0;
		for (k = 0; k < ARRAY_SIZE(i2c_no_probes); k++) {
			if (COMPARE_BUS(bus, k) && COMPARE_ADDR(j, k)) {
				skip = 1;
				break;
			}
		}
		if (skip)
			continue;
#endif
#if CONFIG_IS_ENABLED(DM_I2C)
		ret = dm_i2c_probe(bus, j, 0, &dev);
#else
		ret = i2c_probe(j);
#endif
		if (ret == 0) {
			printf(" %02X", j);
			found++;
		}
	}
	putc ('\n');

#if defined(CONFIG_SYS_I2C_NOPROBES)
	puts ("Excluded chip addresses:");
	for (k = 0; k < ARRAY_SIZE(i2c_no_probes); k++) {
		if (COMPARE_BUS(bus,k))
			printf(" %02X", NO_PROBE_ADDR(k));
	}
	putc ('\n');
#endif

	return (0 == found);
}

Project: u-boot
File: i2c.c

void i2c_init_board(void)
{
}

Project: u-boot
File: i2c.c

static int do_i2c(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
	struct cmd_tbl *c;

#ifdef CONFIG_NEEDS_MANUAL_RELOC
	i2c_reloc();
#endif

	if (argc < 2)
		return CMD_RET_USAGE;

	/* Strip off leading 'i2c' command argument */
	argc--;
	argv++;

	c = find_cmd_tbl(argv[0], &cmd_i2c_sub[0], ARRAY_SIZE(cmd_i2c_sub));

	if (c)
		return c->cmd(cmdtp, flag, argc, argv);
	else
		return CMD_RET_USAGE;
}

Project: u-boot
File: i2c.c

static void show_bus(struct udevice *bus)
{
	struct udevice *dev;

	printf("Bus %d:\t%s", dev_seq(bus), bus->name);
	if (device_active(bus))
		printf("  (active %d)", dev_seq(bus));
	printf("\n");
	for (device_find_first_child(bus, &dev);
	     dev;
	     device_find_next_child(&dev)) {
		struct dm_i2c_chip *chip = dev_get_parent_plat(dev);

		printf("   %02x: %s, offset len %x, flags %x\n",
		       chip->chip_addr, dev->name, chip->offset_len,
		       chip->flags);
	}
}

Project: u-boot
File: i2c.c

static int do_i2c_crc(struct cmd_tbl *cmdtp, int flag, int argc,
		      char *const argv[])
{
	uint	chip;
	ulong	addr;
	uint	alen;
	uint	count;
	uchar	byte;
	ulong	crc;
	ulong	err;
	int ret = 0;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	if (argc < 4)
		return CMD_RET_USAGE;

	/*
	 * Chip is always specified.
	 */
	chip = hextoul(argv[1], NULL);

	/*
	 * Address is always specified.
	 */
	addr = hextoul(argv[2], NULL);
	alen = get_alen(argv[2], DEFAULT_ADDR_LEN);
	if (alen > 3)
		return CMD_RET_USAGE;

#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret && alen != -1)
		ret = i2c_set_chip_offset_len(dev, alen);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);
#endif
	/*
	 * Count is always specified
	 */
	count = hextoul(argv[3], NULL);

	printf ("CRC32 for %08lx ... %08lx ==> ", addr, addr + count - 1);
	/*
	 * CRC a byte at a time.  This is going to be slooow, but hey, the
	 * memories are small and slow too so hopefully nobody notices.
	 */
	crc = 0;
	err = 0;
	while (count-- > 0) {
#if CONFIG_IS_ENABLED(DM_I2C)
		ret = dm_i2c_read(dev, addr, &byte, 1);
#else
		ret = i2c_read(chip, addr, alen, &byte, 1);
#endif
		if (ret)
			err++;
		crc = crc32(crc, &byte, 1);
		addr++;
	}
	if (err > 0)
		i2c_report_err(ret, I2C_ERR_READ);
	else
		printf ("%08lx\n", crc);

	return 0;
}

Project: u-boot
File: i2c.c

static uint get_alen(char *arg, uint default_len)
{
	uint	j;
	uint	alen;

	alen = default_len;
	for (j = 0; j < 8; j++) {
		if (arg[j] == '.') {
			alen = arg[j+1] - '0';
			break;
		} else if (arg[j] == '\0')
			break;
	}
	return alen;
}

Project: u-boot
File: i2c.c

static int do_sdram(struct cmd_tbl *cmdtp, int flag, int argc,
		    char *const argv[])
{
	enum { unknown, EDO, SDRAM, DDR, DDR2, DDR3, DDR4 } type;

	uint	chip;
	u_char	data[128];
	u_char	cksum;
	int	j, ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	static const char *decode_CAS_DDR2[] = {
		" TBD", " 6", " 5", " 4", " 3", " 2", " TBD", " TBD"
	};

	static const char *decode_CAS_default[] = {
		" TBD", " 7", " 6", " 5", " 4", " 3", " 2", " 1"
	};

	static const char *decode_CS_WE_default[] = {
		" TBD", " 6", " 5", " 4", " 3", " 2", " 1", " 0"
	};

	static const char *decode_byte21_default[] = {
		"  TBD (bit 7)\n",
		"  Redundant row address\n",
		"  Differential clock input\n",
		"  Registerd DQMB inputs\n",
		"  Buffered DQMB inputs\n",
		"  On-card PLL\n",
		"  Registered address/control lines\n",
		"  Buffered address/control lines\n"
	};

	static const char *decode_byte22_DDR2[] = {
		"  TBD (bit 7)\n",
		"  TBD (bit 6)\n",
		"  TBD (bit 5)\n",
		"  TBD (bit 4)\n",
		"  TBD (bit 3)\n",
		"  Supports partial array self refresh\n",
		"  Supports 50 ohm ODT\n",
		"  Supports weak driver\n"
	};

	static const char *decode_row_density_DDR2[] = {
		"512 MiB", "256 MiB", "128 MiB", "16 GiB",
		"8 GiB", "4 GiB", "2 GiB", "1 GiB"
	};

	static const char *decode_row_density_default[] = {
		"512 MiB", "256 MiB", "128 MiB", "64 MiB",
		"32 MiB", "16 MiB", "8 MiB", "4 MiB"
	};

	if (argc < 2)
		return CMD_RET_USAGE;

	/*
	 * Chip is always specified.
	 */
	chip = hextoul(argv[1], NULL);

#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret)
		ret = dm_i2c_read(dev, 0, data, sizeof(data));
#else
	ret = i2c_read(chip, 0, 1, data, sizeof(data));
#endif
	if (ret) {
		puts ("No SDRAM Serial Presence Detect found.\n");
		return 1;
	}

	cksum = 0;
	for (j = 0; j < 63; j++) {
		cksum += data[j];
	}
	if (cksum != data[63]) {
		printf ("WARNING: Configuration data checksum failure:\n"
			"  is 0x%02x, calculated 0x%02x\n", data[63], cksum);
	}
	printf ("SPD data revision            %d.%d\n",
		(data[62] >> 4) & 0x0F, data[62] & 0x0F);
	printf ("Bytes used                   0x%02X\n", data[0]);
	printf ("Serial memory size           0x%02X\n", 1 << data[1]);

	puts ("Memory type                  ");
	switch (data[2]) {
	case 2:
		type = EDO;
		puts ("EDO\n");
		break;
	case 4:
		type = SDRAM;
		puts ("SDRAM\n");
		break;
	case 7:
		type = DDR;
		puts("DDR\n");
		break;
	case 8:
		type = DDR2;
		puts ("DDR2\n");
		break;
	case 11:
		type = DDR3;
		puts("DDR3\n");
		break;
	case 12:
		type = DDR4;
		puts("DDR4\n");
		break;
	default:
		type = unknown;
		puts ("unknown\n");
		break;
	}

	puts ("Row address bits             ");
	if ((data[3] & 0x00F0) == 0)
		printf ("%d\n", data[3] & 0x0F);
	else
		printf ("%d/%d\n", data[3] & 0x0F, (data[3] >> 4) & 0x0F);

	puts ("Column address bits          ");
	if ((data[4] & 0x00F0) == 0)
		printf ("%d\n", data[4] & 0x0F);
	else
		printf ("%d/%d\n", data[4] & 0x0F, (data[4] >> 4) & 0x0F);

	switch (type) {
	case DDR2:
		printf ("Number of ranks              %d\n",
			(data[5] & 0x07) + 1);
		break;
	default:
		printf ("Module rows                  %d\n", data[5]);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("Module data width            %d bits\n", data[6]);
		break;
	default:
		printf ("Module data width            %d bits\n",
			(data[7] << 8) | data[6]);
		break;
	}

	puts ("Interface signal levels      ");
	switch(data[8]) {
		case 0:  puts ("TTL 5.0 V\n");	break;
		case 1:  puts ("LVTTL\n");	break;
		case 2:  puts ("HSTL 1.5 V\n");	break;
		case 3:  puts ("SSTL 3.3 V\n");	break;
		case 4:  puts ("SSTL 2.5 V\n");	break;
		case 5:  puts ("SSTL 1.8 V\n");	break;
		default: puts ("unknown\n");	break;
	}

	switch (type) {
	case DDR2:
		printf ("SDRAM cycle time             ");
		print_ddr2_tcyc (data[9]);
		break;
	default:
		printf ("SDRAM cycle time             %d.%d ns\n",
			(data[9] >> 4) & 0x0F, data[9] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("SDRAM access time            0.%d%d ns\n",
			(data[10] >> 4) & 0x0F, data[10] & 0x0F);
		break;
	default:
		printf ("SDRAM access time            %d.%d ns\n",
			(data[10] >> 4) & 0x0F, data[10] & 0x0F);
		break;
	}

	puts ("EDC configuration            ");
	switch (data[11]) {
		case 0:  puts ("None\n");	break;
		case 1:  puts ("Parity\n");	break;
		case 2:  puts ("ECC\n");	break;
		default: puts ("unknown\n");	break;
	}

	if ((data[12] & 0x80) == 0)
		puts ("No self refresh, rate        ");
	else
		puts ("Self refresh, rate           ");

	switch(data[12] & 0x7F) {
		case 0:  puts ("15.625 us\n");	break;
		case 1:  puts ("3.9 us\n");	break;
		case 2:  puts ("7.8 us\n");	break;
		case 3:  puts ("31.3 us\n");	break;
		case 4:  puts ("62.5 us\n");	break;
		case 5:  puts ("125 us\n");	break;
		default: puts ("unknown\n");	break;
	}

	switch (type) {
	case DDR2:
		printf ("SDRAM width (primary)        %d\n", data[13]);
		break;
	default:
		printf ("SDRAM width (primary)        %d\n", data[13] & 0x7F);
		if ((data[13] & 0x80) != 0) {
			printf ("  (second bank)              %d\n",
				2 * (data[13] & 0x7F));
		}
		break;
	}

	switch (type) {
	case DDR2:
		if (data[14] != 0)
			printf ("EDC width                    %d\n", data[14]);
		break;
	default:
		if (data[14] != 0) {
			printf ("EDC width                    %d\n",
				data[14] & 0x7F);

			if ((data[14] & 0x80) != 0) {
				printf ("  (second bank)              %d\n",
					2 * (data[14] & 0x7F));
			}
		}
		break;
	}

	if (DDR2 != type) {
		printf ("Min clock delay, back-to-back random column addresses "
			"%d\n", data[15]);
	}

	puts ("Burst length(s)             ");
	if (data[16] & 0x80) puts (" Page");
	if (data[16] & 0x08) puts (" 8");
	if (data[16] & 0x04) puts (" 4");
	if (data[16] & 0x02) puts (" 2");
	if (data[16] & 0x01) puts (" 1");
	putc ('\n');
	printf ("Number of banks              %d\n", data[17]);

	switch (type) {
	case DDR2:
		puts ("CAS latency(s)              ");
		decode_bits (data[18], decode_CAS_DDR2, 0);
		putc ('\n');
		break;
	default:
		puts ("CAS latency(s)              ");
		decode_bits (data[18], decode_CAS_default, 0);
		putc ('\n');
		break;
	}

	if (DDR2 != type) {
		puts ("CS latency(s)               ");
		decode_bits (data[19], decode_CS_WE_default, 0);
		putc ('\n');
	}

	if (DDR2 != type) {
		puts ("WE latency(s)               ");
		decode_bits (data[20], decode_CS_WE_default, 0);
		putc ('\n');
	}

	switch (type) {
	case DDR2:
		puts ("Module attributes:\n");
		if (data[21] & 0x80)
			puts ("  TBD (bit 7)\n");
		if (data[21] & 0x40)
			puts ("  Analysis probe installed\n");
		if (data[21] & 0x20)
			puts ("  TBD (bit 5)\n");
		if (data[21] & 0x10)
			puts ("  FET switch external enable\n");
		printf ("  %d PLLs on DIMM\n", (data[21] >> 2) & 0x03);
		if (data[20] & 0x11) {
			printf ("  %d active registers on DIMM\n",
				(data[21] & 0x03) + 1);
		}
		break;
	default:
		puts ("Module attributes:\n");
		if (!data[21])
			puts ("  (none)\n");
		else
			decode_bits (data[21], decode_byte21_default, 0);
		break;
	}

	switch (type) {
	case DDR2:
		decode_bits (data[22], decode_byte22_DDR2, 0);
		break;
	default:
		puts ("Device attributes:\n");
		if (data[22] & 0x80) puts ("  TBD (bit 7)\n");
		if (data[22] & 0x40) puts ("  TBD (bit 6)\n");
		if (data[22] & 0x20) puts ("  Upper Vcc tolerance 5%\n");
		else                 puts ("  Upper Vcc tolerance 10%\n");
		if (data[22] & 0x10) puts ("  Lower Vcc tolerance 5%\n");
		else                 puts ("  Lower Vcc tolerance 10%\n");
		if (data[22] & 0x08) puts ("  Supports write1/read burst\n");
		if (data[22] & 0x04) puts ("  Supports precharge all\n");
		if (data[22] & 0x02) puts ("  Supports auto precharge\n");
		if (data[22] & 0x01) puts ("  Supports early RAS# precharge\n");
		break;
	}

	switch (type) {
	case DDR2:
		printf ("SDRAM cycle time (2nd highest CAS latency)        ");
		print_ddr2_tcyc (data[23]);
		break;
	default:
		printf ("SDRAM cycle time (2nd highest CAS latency)        %d."
			"%d ns\n", (data[23] >> 4) & 0x0F, data[23] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("SDRAM access from clock (2nd highest CAS latency) 0."
			"%d%d ns\n", (data[24] >> 4) & 0x0F, data[24] & 0x0F);
		break;
	default:
		printf ("SDRAM access from clock (2nd highest CAS latency) %d."
			"%d ns\n", (data[24] >> 4) & 0x0F, data[24] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("SDRAM cycle time (3rd highest CAS latency)        ");
		print_ddr2_tcyc (data[25]);
		break;
	default:
		printf ("SDRAM cycle time (3rd highest CAS latency)        %d."
			"%d ns\n", (data[25] >> 4) & 0x0F, data[25] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("SDRAM access from clock (3rd highest CAS latency) 0."
			"%d%d ns\n", (data[26] >> 4) & 0x0F, data[26] & 0x0F);
		break;
	default:
		printf ("SDRAM access from clock (3rd highest CAS latency) %d."
			"%d ns\n", (data[26] >> 4) & 0x0F, data[26] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("Minimum row precharge        %d.%02d ns\n",
			(data[27] >> 2) & 0x3F, 25 * (data[27] & 0x03));
		break;
	default:
		printf ("Minimum row precharge        %d ns\n", data[27]);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("Row active to row active min %d.%02d ns\n",
			(data[28] >> 2) & 0x3F, 25 * (data[28] & 0x03));
		break;
	default:
		printf ("Row active to row active min %d ns\n", data[28]);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("RAS to CAS delay min         %d.%02d ns\n",
			(data[29] >> 2) & 0x3F, 25 * (data[29] & 0x03));
		break;
	default:
		printf ("RAS to CAS delay min         %d ns\n", data[29]);
		break;
	}

	printf ("Minimum RAS pulse width      %d ns\n", data[30]);

	switch (type) {
	case DDR2:
		puts ("Density of each row          ");
		decode_bits (data[31], decode_row_density_DDR2, 1);
		putc ('\n');
		break;
	default:
		puts ("Density of each row          ");
		decode_bits (data[31], decode_row_density_default, 1);
		putc ('\n');
		break;
	}

	switch (type) {
	case DDR2:
		puts ("Command and Address setup    ");
		if (data[32] >= 0xA0) {
			printf ("1.%d%d ns\n",
				((data[32] >> 4) & 0x0F) - 10, data[32] & 0x0F);
		} else {
			printf ("0.%d%d ns\n",
				((data[32] >> 4) & 0x0F), data[32] & 0x0F);
		}
		break;
	default:
		printf ("Command and Address setup    %c%d.%d ns\n",
			(data[32] & 0x80) ? '-' : '+',
			(data[32] >> 4) & 0x07, data[32] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		puts ("Command and Address hold     ");
		if (data[33] >= 0xA0) {
			printf ("1.%d%d ns\n",
				((data[33] >> 4) & 0x0F) - 10, data[33] & 0x0F);
		} else {
			printf ("0.%d%d ns\n",
				((data[33] >> 4) & 0x0F), data[33] & 0x0F);
		}
		break;
	default:
		printf ("Command and Address hold     %c%d.%d ns\n",
			(data[33] & 0x80) ? '-' : '+',
			(data[33] >> 4) & 0x07, data[33] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("Data signal input setup      0.%d%d ns\n",
			(data[34] >> 4) & 0x0F, data[34] & 0x0F);
		break;
	default:
		printf ("Data signal input setup      %c%d.%d ns\n",
			(data[34] & 0x80) ? '-' : '+',
			(data[34] >> 4) & 0x07, data[34] & 0x0F);
		break;
	}

	switch (type) {
	case DDR2:
		printf ("Data signal input hold       0.%d%d ns\n",
			(data[35] >> 4) & 0x0F, data[35] & 0x0F);
		break;
	default:
		printf ("Data signal input hold       %c%d.%d ns\n",
			(data[35] & 0x80) ? '-' : '+',
			(data[35] >> 4) & 0x07, data[35] & 0x0F);
		break;
	}

	puts ("Manufacturer's JEDEC ID      ");
	for (j = 64; j <= 71; j++)
		printf ("%02X ", data[j]);
	putc ('\n');
	printf ("Manufacturing Location       %02X\n", data[72]);
	puts ("Manufacturer's Part Number   ");
	for (j = 73; j <= 90; j++)
		printf ("%02X ", data[j]);
	putc ('\n');
	printf ("Revision Code                %02X %02X\n", data[91], data[92]);
	printf ("Manufacturing Date           %02X %02X\n", data[93], data[94]);
	puts ("Assembly Serial Number       ");
	for (j = 95; j <= 98; j++)
		printf ("%02X ", data[j]);
	putc ('\n');

	if (DDR2 != type) {
		printf ("Speed rating                 PC%d\n",
			data[126] == 0x66 ? 66 : data[126]);
	}
	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_nm(struct cmd_tbl *cmdtp, int flag, int argc,
		     char *const argv[])
{
	return mod_i2c_mem (cmdtp, 0, flag, argc, argv);
}

Project: u-boot
File: i2c.c

static int do_i2c_loop(struct cmd_tbl *cmdtp, int flag, int argc,
		       char *const argv[])
{
	uint	chip;
	uint	alen;
	uint	addr;
	uint	length;
	u_char	bytes[16];
	int	delay;
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	if (argc < 3)
		return CMD_RET_USAGE;

	/*
	 * Chip is always specified.
	 */
	chip = hextoul(argv[1], NULL);

	/*
	 * Address is always specified.
	 */
	addr = hextoul(argv[2], NULL);
	alen = get_alen(argv[2], DEFAULT_ADDR_LEN);
	if (alen > 3)
		return CMD_RET_USAGE;
#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret && alen != -1)
		ret = i2c_set_chip_offset_len(dev, alen);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_WRITE);
#endif

	/*
	 * Length is the number of objects, not number of bytes.
	 */
	length = 1;
	length = hextoul(argv[3], NULL);
	if (length > sizeof(bytes))
		length = sizeof(bytes);

	/*
	 * The delay time (uSec) is optional.
	 */
	delay = 1000;
	if (argc > 3)
		delay = dectoul(argv[4], NULL);
	/*
	 * Run the loop...
	 */
	while (1) {
#if CONFIG_IS_ENABLED(DM_I2C)
		ret = dm_i2c_read(dev, addr, bytes, length);
#else
		ret = i2c_read(chip, addr, alen, bytes, length);
#endif
		if (ret)
			i2c_report_err(ret, I2C_ERR_READ);
		udelay(delay);
	}

	/* NOTREACHED */
	return 0;
}

Project: u-boot
File: i2c.c

static __maybe_unused void i2c_reloc(void)
{
	static int relocated;

	if (!relocated) {
		fixup_cmdtable(cmd_i2c_sub, ARRAY_SIZE(cmd_i2c_sub));
		relocated = 1;
	};
}

Project: u-boot
File: i2c.c

static int do_i2c_write(struct cmd_tbl *cmdtp, int flag, int argc,
			char *const argv[])
{
	uint	chip;
	uint	devaddr, length;
	uint	alen;
	u_char  *memaddr;
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
	struct dm_i2c_chip *i2c_chip;
#endif

	if ((argc < 5) || (argc > 6))
		return cmd_usage(cmdtp);

	/*
	 * memaddr is the address where to store things in memory
	 */
	memaddr = (u_char *)hextoul(argv[1], NULL);

	/*
	 * I2C chip address
	 */
	chip = hextoul(argv[2], NULL);

	/*
	 * I2C data address within the chip.  This can be 1 or
	 * 2 bytes long.  Some day it might be 3 bytes long :-).
	 */
	devaddr = hextoul(argv[3], NULL);
	alen = get_alen(argv[3], DEFAULT_ADDR_LEN);
	if (alen > 3)
		return cmd_usage(cmdtp);

	/*
	 * Length is the number of bytes.
	 */
	length = hextoul(argv[4], NULL);

#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret && alen != -1)
		ret = i2c_set_chip_offset_len(dev, alen);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_WRITE);
	i2c_chip = dev_get_parent_plat(dev);
	if (!i2c_chip)
		return i2c_report_err(ret, I2C_ERR_WRITE);
#endif

	if (argc == 6 && !strcmp(argv[5], "-s")) {
		/*
		 * Write all bytes in a single I2C transaction. If the target
		 * device is an EEPROM, it is your responsibility to not cross
		 * a page boundary. No write delay upon completion, take this
		 * into account if linking commands.
		 */
#if CONFIG_IS_ENABLED(DM_I2C)
		i2c_chip->flags &= ~DM_I2C_CHIP_WR_ADDRESS;
		ret = dm_i2c_write(dev, devaddr, memaddr, length);
#else
		ret = i2c_write(chip, devaddr, alen, memaddr, length);
#endif
		if (ret)
			return i2c_report_err(ret, I2C_ERR_WRITE);
	} else {
		/*
		 * Repeated addressing - perform <length> separate
		 * write transactions of one byte each
		 */
		while (length-- > 0) {
#if CONFIG_IS_ENABLED(DM_I2C)
			i2c_chip->flags |= DM_I2C_CHIP_WR_ADDRESS;
			ret = dm_i2c_write(dev, devaddr++, memaddr++, 1);
#else
			ret = i2c_write(chip, devaddr++, alen, memaddr++, 1);
#endif
			if (ret)
				return i2c_report_err(ret, I2C_ERR_WRITE);
/*
 * No write delay with FRAM devices.
 */
#if !defined(CONFIG_SYS_I2C_FRAM)
			udelay(11000);
#endif
		}
	}
	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_read(struct cmd_tbl *cmdtp, int flag, int argc,
		       char *const argv[])
{
	uint	chip;
	uint	devaddr, length;
	uint	alen;
	u_char  *memaddr;
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	if (argc != 5)
		return CMD_RET_USAGE;

	/*
	 * I2C chip address
	 */
	chip = hextoul(argv[1], NULL);

	/*
	 * I2C data address within the chip.  This can be 1 or
	 * 2 bytes long.  Some day it might be 3 bytes long :-).
	 */
	devaddr = hextoul(argv[2], NULL);
	alen = get_alen(argv[2], DEFAULT_ADDR_LEN);
	if (alen > 3)
		return CMD_RET_USAGE;

	/*
	 * Length is the number of objects, not number of bytes.
	 */
	length = hextoul(argv[3], NULL);

	/*
	 * memaddr is the address where to store things in memory
	 */
	memaddr = (u_char *)hextoul(argv[4], NULL);

#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret && alen != -1)
		ret = i2c_set_chip_offset_len(dev, alen);
	if (!ret)
		ret = dm_i2c_read(dev, devaddr, memaddr, length);
#else
	ret = i2c_read(chip, devaddr, alen, memaddr, length);
#endif
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);

	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_bus_speed(struct cmd_tbl *cmdtp, int flag, int argc,
			    char *const argv[])
{
	int speed, ret=0;

#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *bus;

	if (i2c_get_cur_bus(&bus))
		return 1;
#endif
	if (argc == 1) {
#if CONFIG_IS_ENABLED(DM_I2C)
		speed = dm_i2c_get_bus_speed(bus);
#else
		speed = i2c_get_bus_speed();
#endif
		/* querying current speed */
		printf("Current bus speed=%d\n", speed);
	} else {
		speed = dectoul(argv[1], NULL);
		printf("Setting bus speed to %d Hz\n", speed);
#if CONFIG_IS_ENABLED(DM_I2C)
		ret = dm_i2c_set_bus_speed(bus, speed);
#else
		ret = i2c_set_bus_speed(speed);
#endif
		if (ret)
			printf("Failure changing bus speed (%d)\n", ret);
	}

	return ret ? CMD_RET_FAILURE : 0;
}

Project: u-boot
File: i2c.c

static int mod_i2c_mem(struct cmd_tbl *cmdtp, int incrflag, int flag, int argc,
		       char *const argv[])
{
	uint	chip;
	ulong	addr;
	int	alen;
	ulong	data;
	int	size = 1;
	int	nbytes;
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	if (argc != 3)
		return CMD_RET_USAGE;

	bootretry_reset_cmd_timeout();	/* got a good command to get here */
	/*
	 * We use the last specified parameters, unless new ones are
	 * entered.
	 */
	chip = i2c_mm_last_chip;
	addr = i2c_mm_last_addr;
	alen = i2c_mm_last_alen;

	if ((flag & CMD_FLAG_REPEAT) == 0) {
		/*
		 * New command specified.  Check for a size specification.
		 * Defaults to byte if no or incorrect specification.
		 */
		size = cmd_get_data_size(argv[0], 1);

		/*
		 * Chip is always specified.
		 */
		chip = hextoul(argv[1], NULL);

		/*
		 * Address is always specified.
		 */
		addr = hextoul(argv[2], NULL);
		alen = get_alen(argv[2], DEFAULT_ADDR_LEN);
		if (alen > 3)
			return CMD_RET_USAGE;
	}

#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret && alen != -1)
		ret = i2c_set_chip_offset_len(dev, alen);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_WRITE);
#endif

	/*
	 * Print the address, followed by value.  Then accept input for
	 * the next value.  A non-converted value exits.
	 */
	do {
		printf("%08lx:", addr);
#if CONFIG_IS_ENABLED(DM_I2C)
		ret = dm_i2c_read(dev, addr, (uchar *)&data, size);
#else
		ret = i2c_read(chip, addr, alen, (uchar *)&data, size);
#endif
		if (ret)
			return i2c_report_err(ret, I2C_ERR_READ);

		data = cpu_to_be32(data);
		if (size == 1)
			printf(" %02lx", (data >> 24) & 0x000000FF);
		else if (size == 2)
			printf(" %04lx", (data >> 16) & 0x0000FFFF);
		else
			printf(" %08lx", data);

		nbytes = cli_readline(" ? ");
		if (nbytes == 0) {
			/*
			 * <CR> pressed as only input, don't modify current
			 * location and move to next.
			 */
			if (incrflag)
				addr += size;
			nbytes = size;
			/* good enough to not time out */
			bootretry_reset_cmd_timeout();
		}
#ifdef CONFIG_BOOT_RETRY_TIME
		else if (nbytes == -2)
			break;	/* timed out, exit the command	*/
#endif
		else {
			char *endp;

			data = hextoul(console_buffer, &endp);
			if (size == 1)
				data = data << 24;
			else if (size == 2)
				data = data << 16;
			data = be32_to_cpu(data);
			nbytes = endp - console_buffer;
			if (nbytes) {
				/*
				 * good enough to not time out
				 */
				bootretry_reset_cmd_timeout();
#if CONFIG_IS_ENABLED(DM_I2C)
				ret = dm_i2c_write(dev, addr, (uchar *)&data,
						   size);
#else
				ret = i2c_write(chip, addr, alen,
						(uchar *)&data, size);
#endif
				if (ret)
					return i2c_report_err(ret,
							      I2C_ERR_WRITE);
#if CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS > 0
				udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
#endif
				if (incrflag)
					addr += size;
			}
		}
	} while (nbytes);

	i2c_mm_last_chip = chip;
	i2c_mm_last_addr = addr;
	i2c_mm_last_alen = alen;

	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_reset(struct cmd_tbl *cmdtp, int flag, int argc,
			char *const argv[])
{
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *bus;

	if (i2c_get_cur_bus(&bus))
		return CMD_RET_FAILURE;
	if (i2c_deblock(bus)) {
		printf("Error: Not supported by the driver\n");
		return CMD_RET_FAILURE;
	}
#elif CONFIG_IS_ENABLED(SYS_I2C_LEGACY)
	i2c_init(I2C_ADAP->speed, I2C_ADAP->slaveaddr);
#endif
	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_bus_num(struct cmd_tbl *cmdtp, int flag, int argc,
			  char *const argv[])
{
	int		ret = 0;
	int	bus_no;

	if (argc == 1) {
		/* querying current setting */
#if CONFIG_IS_ENABLED(DM_I2C)
		struct udevice *bus;

		if (!i2c_get_cur_bus(&bus))
			bus_no = dev_seq(bus);
		else
			bus_no = -1;
#else
		bus_no = i2c_get_bus_num();
#endif
		printf("Current bus is %d\n", bus_no);
	} else {
		bus_no = dectoul(argv[1], NULL);
#if CONFIG_IS_ENABLED(SYS_I2C_LEGACY)
		if (bus_no >= CONFIG_SYS_NUM_I2C_BUSES) {
			printf("Invalid bus %d\n", bus_no);
			return -1;
		}
#endif
		printf("Setting bus to %d\n", bus_no);
#if CONFIG_IS_ENABLED(DM_I2C)
		ret = cmd_i2c_set_bus_num(bus_no);
#else
		ret = i2c_set_bus_num(bus_no);
#endif
		if (ret)
			printf("Failure changing bus number (%d)\n", ret);
	}

	return ret ? CMD_RET_FAILURE : 0;
}

Project: u-boot
File: i2c.c

static int i2c_report_err(int ret, enum i2c_err_op op)
{
	printf("Error %s the chip: %d\n",
	       op == I2C_ERR_READ ? "reading" : "writing", ret);

	return CMD_RET_FAILURE;
}

Project: u-boot
File: i2c.c

static int do_i2c_mw(struct cmd_tbl *cmdtp, int flag, int argc,
		     char *const argv[])
{
	uint	chip;
	ulong	addr;
	uint	alen;
	uchar	byte;
	uint	count;
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	if ((argc < 4) || (argc > 5))
		return CMD_RET_USAGE;

	/*
	 * Chip is always specified.
	 */
	chip = hextoul(argv[1], NULL);

	/*
	 * Address is always specified.
	 */
	addr = hextoul(argv[2], NULL);
	alen = get_alen(argv[2], DEFAULT_ADDR_LEN);
	if (alen > 3)
		return CMD_RET_USAGE;

#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret && alen != -1)
		ret = i2c_set_chip_offset_len(dev, alen);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_WRITE);
#endif
	/*
	 * Value to write is always specified.
	 */
	byte = hextoul(argv[3], NULL);

	/*
	 * Optional count
	 */
	if (argc == 5)
		count = hextoul(argv[4], NULL);
	else
		count = 1;

	while (count-- > 0) {
#if CONFIG_IS_ENABLED(DM_I2C)
		ret = dm_i2c_write(dev, addr++, &byte, 1);
#else
		ret = i2c_write(chip, addr++, alen, &byte, 1);
#endif
		if (ret)
			return i2c_report_err(ret, I2C_ERR_WRITE);
		/*
		 * Wait for the write to complete.  The write can take
		 * up to 10mSec (we allow a little more time).
		 */
/*
 * No write delay with FRAM devices.
 */
#if !defined(CONFIG_SYS_I2C_FRAM)
		udelay(11000);
#endif
	}

	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_olen(struct cmd_tbl *cmdtp, int flag, int argc,
		       char *const argv[])
{
	struct udevice *dev;
	uint olen;
	int chip;
	int ret;

	if (argc < 2)
		return CMD_RET_USAGE;

	chip = hextoul(argv[1], NULL);
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);

	if (argc > 2) {
		olen = hextoul(argv[2], NULL);
		ret = i2c_set_chip_offset_len(dev, olen);
	} else  {
		ret = i2c_get_chip_offset_len(dev);
		if (ret >= 0) {
			printf("%x\n", ret);
			ret = 0;
		}
	}
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);

	return 0;
}

Project: u-boot
File: i2c.c

static void decode_bits (u_char const b, char const *str[], int const do_once)
{
	u_char mask;

	for (mask = 0x80; mask != 0x00; mask >>= 1, ++str) {
		if (b & mask) {
			puts (*str);
			if (do_once)
				return;
		}
	}
}

Project: u-boot
File: i2c.c

static int i2c_get_cur_bus(struct udevice **busp)
{
#ifdef CONFIG_I2C_SET_DEFAULT_BUS_NUM
	if (!i2c_cur_bus) {
		if (cmd_i2c_set_bus_num(CONFIG_I2C_DEFAULT_BUS_NUMBER)) {
			printf("Default I2C bus %d not found\n",
			       CONFIG_I2C_DEFAULT_BUS_NUMBER);
			return -ENODEV;
		}
	}
#endif

	if (!i2c_cur_bus) {
		puts("No I2C bus selected\n");
		return -ENODEV;
	}
	*busp = i2c_cur_bus;

	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_mm(struct cmd_tbl *cmdtp, int flag, int argc,
		     char *const argv[])
{
	return mod_i2c_mem (cmdtp, 1, flag, argc, argv);
}

Project: u-boot
File: i2c.c

static void print_ddr2_tcyc (u_char const b)
{
	printf ("%d.", (b >> 4) & 0x0F);
	switch (b & 0x0F) {
	case 0x0:
	case 0x1:
	case 0x2:
	case 0x3:
	case 0x4:
	case 0x5:
	case 0x6:
	case 0x7:
	case 0x8:
	case 0x9:
		printf ("%d ns\n", b & 0x0F);
		break;
	case 0xA:
		puts ("25 ns\n");
		break;
	case 0xB:
		puts ("33 ns\n");
		break;
	case 0xC:
		puts ("66 ns\n");
		break;
	case 0xD:
		puts ("75 ns\n");
		break;
	default:
		puts ("?? ns\n");
		break;
	}
}

Project: u-boot
File: i2c.c

static int do_i2c_flags(struct cmd_tbl *cmdtp, int flag, int argc,
			char *const argv[])
{
	struct udevice *dev;
	uint flags;
	int chip;
	int ret;

	if (argc < 2)
		return CMD_RET_USAGE;

	chip = hextoul(argv[1], NULL);
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);

	if (argc > 2) {
		flags = hextoul(argv[2], NULL);
		ret = i2c_set_chip_flags(dev, flags);
	} else  {
		ret = i2c_get_chip_flags(dev, &flags);
		if (!ret)
			printf("%x\n", flags);
	}
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);

	return 0;
}

Project: u-boot
File: i2c.c

static int do_i2c_md(struct cmd_tbl *cmdtp, int flag, int argc,
		     char *const argv[])
{
	uint	chip;
	uint	addr, length;
	uint	alen;
	uint	j, nbytes, linebytes;
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	/* We use the last specified parameters, unless new ones are
	 * entered.
	 */
	chip   = i2c_dp_last_chip;
	addr   = i2c_dp_last_addr;
	alen   = i2c_dp_last_alen;
	length = i2c_dp_last_length;

	if (argc < 3)
		return CMD_RET_USAGE;

	if ((flag & CMD_FLAG_REPEAT) == 0) {
		/*
		 * New command specified.
		 */

		/*
		 * I2C chip address
		 */
		chip = hextoul(argv[1], NULL);

		/*
		 * I2C data address within the chip.  This can be 1 or
		 * 2 bytes long.  Some day it might be 3 bytes long :-).
		 */
		addr = hextoul(argv[2], NULL);
		alen = get_alen(argv[2], DEFAULT_ADDR_LEN);
		if (alen > 3)
			return CMD_RET_USAGE;

		/*
		 * If another parameter, it is the length to display.
		 * Length is the number of objects, not number of bytes.
		 */
		if (argc > 3)
			length = hextoul(argv[3], NULL);
	}

#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret && alen != -1)
		ret = i2c_set_chip_offset_len(dev, alen);
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);
#endif

	/*
	 * Print the lines.
	 *
	 * We buffer all read data, so we can make sure data is read only
	 * once.
	 */
	nbytes = length;
	do {
		unsigned char	linebuf[DISP_LINE_LEN];
		unsigned char	*cp;

		linebytes = (nbytes > DISP_LINE_LEN) ? DISP_LINE_LEN : nbytes;

#if CONFIG_IS_ENABLED(DM_I2C)
		ret = dm_i2c_read(dev, addr, linebuf, linebytes);
#else
		ret = i2c_read(chip, addr, alen, linebuf, linebytes);
#endif
		if (ret)
			return i2c_report_err(ret, I2C_ERR_READ);
		else {
			printf("%04x:", addr);
			cp = linebuf;
			for (j=0; j<linebytes; j++) {
				printf(" %02x", *cp++);
				addr++;
			}
			puts ("    ");
			cp = linebuf;
			for (j=0; j<linebytes; j++) {
				if ((*cp < 0x20) || (*cp > 0x7e))
					puts (".");
				else
					printf("%c", *cp);
				cp++;
			}
			putc ('\n');
		}
		nbytes -= linebytes;
	} while (nbytes > 0);

	i2c_dp_last_chip   = chip;
	i2c_dp_last_addr   = addr;
	i2c_dp_last_alen   = alen;
	i2c_dp_last_length = length;

	return 0;
}

Project: u-boot
File: i2c.c

int do_edid(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
	uint chip;
	struct edid1_info edid;
	int ret;
#if CONFIG_IS_ENABLED(DM_I2C)
	struct udevice *dev;
#endif

	if (argc < 2) {
		cmd_usage(cmdtp);
		return 1;
	}

	chip = hextoul(argv[1], NULL);
#if CONFIG_IS_ENABLED(DM_I2C)
	ret = i2c_get_cur_bus_chip(chip, &dev);
	if (!ret)
		ret = dm_i2c_read(dev, 0, (uchar *)&edid, sizeof(edid));
#else
	ret = i2c_read(chip, 0, 1, (uchar *)&edid, sizeof(edid));
#endif
	if (ret)
		return i2c_report_err(ret, I2C_ERR_READ);

	if (edid_check_info(&edid)) {
		puts("Content isn't valid EDID.\n");
		return 1;
	}

	edid_print_info(&edid);
	return 0;

}

Project: u-boot
File: i2c.c

static int do_i2c_show_bus(struct cmd_tbl *cmdtp, int flag, int argc,
			   char *const argv[])
{
	if (argc == 1) {
		/* show all busses */
#if CONFIG_IS_ENABLED(DM_I2C)
		struct udevice *bus;
		struct uclass *uc;
		int ret;

		ret = uclass_get(UCLASS_I2C, &uc);
		if (ret)
			return CMD_RET_FAILURE;
		uclass_foreach_dev(bus, uc)
			show_bus(bus);
#else
		int i;

		for (i = 0; i < CONFIG_SYS_NUM_I2C_BUSES; i++) {
			printf("Bus %d:\t%s", i, I2C_ADAP_NR(i)->name);
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
			int j;

			for (j = 0; j < CONFIG_SYS_I2C_MAX_HOPS; j++) {
				if (i2c_bus[i].next_hop[j].chip == 0)
					break;
				printf("->%s@0x%2x:%d",
				       i2c_bus[i].next_hop[j].mux.name,
				       i2c_bus[i].next_hop[j].chip,
				       i2c_bus[i].next_hop[j].channel);
			}
#endif
			printf("\n");
		}
#endif
	} else {
		int i;

		/* show specific bus */
		i = dectoul(argv[1], NULL);
#if CONFIG_IS_ENABLED(DM_I2C)
		struct udevice *bus;
		int ret;

		ret = uclass_get_device_by_seq(UCLASS_I2C, i, &bus);
		if (ret) {
			printf("Invalid bus %d: err=%d\n", i, ret);
			return CMD_RET_FAILURE;
		}
		show_bus(bus);
#else
		if (i >= CONFIG_SYS_NUM_I2C_BUSES) {
			printf("Invalid bus %d\n", i);
			return -1;
		}
		printf("Bus %d:\t%s", i, I2C_ADAP_NR(i)->name);
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
			int j;
			for (j = 0; j < CONFIG_SYS_I2C_MAX_HOPS; j++) {
				if (i2c_bus[i].next_hop[j].chip == 0)
					break;
				printf("->%s@0x%2x:%d",
				       i2c_bus[i].next_hop[j].mux.name,
				       i2c_bus[i].next_hop[j].chip,
				       i2c_bus[i].next_hop[j].channel);
			}
#endif
		printf("\n");
#endif
	}

	return 0;
}

Project: u-boot
File: i2c.c

static int i2c_get_cur_bus_chip(uint chip_addr, struct udevice **devp)
{
	struct udevice *bus;
	int ret;

	ret = i2c_get_cur_bus(&bus);
	if (ret)
		return ret;

	return i2c_get_chip(bus, chip_addr, 1, devp);
}